How to Calculate Battery Backup Time
You will commonly find battery backups in offices, hospitals and other locations where keeping systems up and running is essential. As long as electricity is flowing, the battery backup will sit quietly out of the way. The amount of time that the battery will last is dependent on the power consumption of the devices that are attached.
What You'll Need:
- Pen
- Paper
- Calculator
- User manual
- You'll first need to determine the power efficiency factor of your battery backup. The battery will use a DC-to-AC converter. The converter will store live currents in a rechargeable battery pack, and then transform the stored energy into an electric current. You'll need to refer to the user manual in order to identify the power efficiency factor to the converter.
- Identify the ampere hours (AH) for the battery backup. You can find this information on the label posted on the back of the battery backup. This information is typically reflected in the form of voltage. Once you have identified the AH for each backup, add all the numbers together to calculate the combined total of ampere hours.
- Multiple the ampere hours of the battery backup by the amount of the power efficiency factor. The end result is a number that is reflective of the voltage output of the battery backup system.
- Look at the power supply or the user manual of the devices that are connected to the battery backup system. The power supply will also contain information to identify the voltage and amperage of the device. You'll need to multiply these numbers together to calculate the devices power consumption per the volt amperes (VA).
- Insert the device power consumption number into a calculator, then divide the number by the amount of the voltage output of the battery backup. When you divide each of these numbers you will be able to tell how much electric current will be drawn through the device.
- Begin a new calculation; insert the amount of the power efficiency factor that was determined in the beginning. Divide the number by the amount of electric current drawn. When you divide the numbers you can tall the maximum amount of time that the battery backup can provide electric current to your devices. The time is calculated in hours.